Identification and Measurements of Strong Brønsted Acid Site in Ultrastable Y (USY) Zeolite
- 13 December 2005
- journal article
- research article
- Published by American Chemical Society (ACS) in The Journal of Physical Chemistry B
- Vol. 110 (1), 264-269
- https://doi.org/10.1021/jp054442e
Abstract
By using the IRMS-TPD method in which IR (infrared) and MS (mass spectroscopy) worked together, acid sites of USY (ultrastable Y) zeolite were studied. A new band of OH playing a role of Brønsted acid was clearly detected on Na2H2−ethylenediaminetetraacetic acid (EDTA)-treated USY at 3595 cm-1 during an elevation in temperature after the adsorption of ammonia. MS-measured TPD (temperature-programmed desorption) of NH3 and IR-measured TPD of the NH4+ cation coincided well to show that this zeolite consisted of the Brønsted acid sites. The MS-TPD profile at higher temperatures corresponded to the IR-TPD of the 3595-cm-1 band, and therefore, this OH was identified as a strong acid site. From comparison between IR-TPD of OH and MS-TPD, numbers of three kinds of Brønsted OH (i.e., those in super and sodalite cages of a Y zeolite structure) and created strong Brønsted acid site were quantified. On the other hand, strength of the Brønsted acid site ΔH was determined individually by a simulation method, where the corrected IR-TPD of OH was simulated based on the proposed equation. Thus, a new strong Brønsted acid site was identified in the EDTA-treated USY, and the amount and strength was measured quantitatively.This publication has 26 references indexed in Scilit:
- Distribution of Acid Sites in MordeniteChemistry Letters, 2005
- Effect of leaching agent in the dealumination of stabilized Y zeolitesMicroporous and Mesoporous Materials, 2000
- Acidic Property of Y- and Mordenite-Type Zeolites with High Aluminum Concentration under Dry ConditionsThe Journal of Physical Chemistry B, 2000
- Changes in Structural and Electronic Properties of the Zeolite Framework Induced by Extraframework Al and La in H-USY and La(x)NaY: A29Si and27Al MAS NMR and27Al MQ MAS NMR StudyThe Journal of Physical Chemistry B, 2000
- Towards understanding the enhanced cracking activity of steamed Y zeolitesCatalysis Today, 1999
- Simultaneous Quantification of Brønsted- and Lewis-Acid Sites in a USY ZeoliteJournal of Catalysis, 1999
- The roles of acid strength and pore diffusion in the enhanced cracking activity of steamed Y zeolitesApplied Catalysis A: General, 1999
- FTIR study of weak hydrogen bonding of Broensted hydroxyls in zeolites and aluminophosphatesThe Journal of Physical Chemistry, 1994
- Solid-state NMR study using trimethylphosphine as a probe of acid sites in normal and dealuminated zeolite YThe Journal of Physical Chemistry, 1989
- Acid catalysis by dealuminated zeolite-Y I. Methanol dehydration and cumene dealkylationJournal of Catalysis, 1986